IEEE NJ Coast Section Seminar on Wireless LAN & IP Telephony Session W3 Toward 4G Networks Ramachandran Ramjee, Ph.D.
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Wide-Area Wireless Standards Evolution 3G/ IMT-2000 Capable Existing Spectrum New Spectrum IS-95-A/ cdmaOne IS-95-A/ cdmaOne IS-95-B/ cdmaOne IS-95-B/ cdmaOne IS-136 TDMA IS-136 TDMA 136 HS EDGE 136 HS EDGE GSM GSM GPRS EDGE WCDMA cdma2000 1X (1.25 MHz) cdma2000 3X (5 MHz) HSCSD 1XEV DO: HDR (1.25 MHz) 2G“2.5G”1G Analog AMPS Analog AMPS TACS
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Other wireless standards /802.11b Mbps - uses 2.4GHz spectrum a - 54 Mbps - Orthogonal Frequency Division Multiplexing (OFDM) HiperLan2 - 50Mbps - local-area networks - uses 5GHz spectrum Bluetooth kbps - very limited range using 2.4GHz spectrum ARDIS Kbps - IBM/Motorola - slotted CSMA MOBITEX Kbps - RAM mobile-slotted CSMA CDPD Kbps - DSMA/CD using AMPS Metricom - Frequency Hopped SS Kbps, 128 kbps upgrade - uses the ISM 900 Mhz band iDEN - 20kbps - uses Mobile IP, supports WAP DECT/CT2 - cordless, low-mobility - 32kbps - FDMA/TDMA PHS - cordless system for microcell/indoor use, Japan Kbps - TDMA iMode Kbps - packet data service, currently uses PDC WAP - Wireless Application Protocol - currently circuit-switched data
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Observations The ‘G’ in #G stands for Generation and typically refers to the generation of wide-area wireless network’s air interface While the 4G air interface has not been standardized yet, a plethora of wireless standards are prevalent and will continue to co-exist Dominant among these are CDMA2000, WCDMA, and based systems Today, each of these air interfaces has its own network architecture standards though the network provides similar functionality of mobility and location management *A unified network architecture based on IP that provides a common mobility and location management mechanism can serve as the 4G network of the future while different air interfaces simply plug into this network
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Outline Motivation IP Mobility –Macro-mobility: Mobile IP –Micro-mobility: HAWAII IP Paging –HA/FA paging –Domain paging Interworking of Wireless LANs with 3G Networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Motivation: Why IP? Migration of wireless access networks to IP allows – Support for anticipated growth of the wireless Internet access merging of services for wireline and wireless networks merging of wireless voice and data networks – Reduced product and operational costs of IP infrastructure availability of “commodity” hardware, software, and services increased efficiency of packet-based networks for combining voice and data
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Industry Directions for Wireless Networking Cellular Telecom Approach – Efforts to define wireless data networking standard (General Packet Radio Service/GPRS, UMTS) begin before full impact of Internet explosion is felt Internet-Based Approach – Use Internet standards for networking and mobility with extensions to inter-operate and support cellular air interfaces (e.g., GPRS, CDMA) GPRS/UMTS standards begin M Internet Users M Internet Users FPLMTS standards begin 1st UMTS customers
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Clash of models Telecom/cellular model Approach: Extend current wireless circuit-based infrastructure to support wireless internet data – Flexibility at the cost of complexity and efficiency (e.g. X.25 support in GPRS, PPP support in CDMA) + Rich functionality through experience (e.g., paging, micro- mobility) Internet model Approach: Extend current internet data-based infrastructure to support wireless internet data + Simplicity using IP (support other protocols, e.g. X.25, through tunneling if necessary) – Missing functionality (e.g., paging, micro-mobility)
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Emerging Mobile Packet Networks: GPRS and UMTS Compatible with cellular telecom networks + may be deployed leveraging existing infrastructure – requires separate advances from the Internet Specialized nodes manage mobility and forward packets + requires no changes to fixed hosts or intermediate routers – results in tunneling and triangular routing – special failure recovery mechanisms needed Inter-SGSN handoffs always managed by GGSN – high update overhead – slow handoffs Intranet MD SGSN GGSN Host Regular routing Tunneled packets using GTP Internet SGSN Radio Access Networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Emerging Mobile Packet Networks: CDMA2000 and (Mobile IPv4) Compatible with regular IP networks and hosts + most Internet advances apply Specialized agents manage mobility and forward packets + requires no changes to fixed hosts or routers – results in tunneling and triangular routing – special failure recovery mechanisms needed Handoffs always managed by Home Agent – high update overhead – slow handoffs MD FA HA Host Internet Regular routing Tunneled packets using Mobile IP FA Radio Access Networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Trends Local and Wide-area wireless data networks – high and low mobility users IP functionality in access network elements including base stations – homogeneous IP-based access network Diverse applications – quality of service support necessary * Mobility has to be processed locally Trends
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Micro-mobility: Design Goals Scalability – process updates locally Limit disruption – forward packets if necessary Efficiency – avoid tunneling where possible Quality of Service (QoS) support – local restoration of reservations Reliability – leverage fault detection mechanisms in routing protocols Transparency – minimal impact at the mobile host
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Hierarchy through domains – Mobile-IP for movement between domains – HAWAII Path Setup for movement within domain Users retain their unique IP address while moving within a domain – Home address could be dynamically assigned – Co-located care-of address used in foreign domain * Unique and unchanging address limits updates to Home Agent and simplifies QoS support in the network Hierarchy and unique address
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII: Enhanced Mobile IP Distributed control: Reliability and scalability – host-based routing entries in routers on path to mobile Localized mobility management: Fast handoffs – updates only reach routers affected by movement Minimized or Eliminated Tunneling: Efficient routing – dynamic, public address assignment to mobile devices Domain Router RR RRRR Domain Router RR RRRR Local mobility Mobile IP Internet MD
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII Mobile IP Internet >port 4, > port 3, >wireless, R R MY IP: BS IP: R R R Domain Root Router 2 Domain Root Router 1 5 BS BS2BS3BS4 1 Power-up
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Design Principle III:Soft-state Host-based routing entries maintained as soft-state Base-stations and mobile hosts periodically refresh the soft-state HAWAII leverages routing protocol failure detection and recovery mechanisms to recover from failures * Recovery from link/router failures Soft-State
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII Mobile IP Failure Recovery Internet >port 3, > port 4, >wireless, R R MY IP: BS IP: R R R Domain Root Router 2 Domain Root Router 1 5 BS1 2 3 BS2BS3BS4 1
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Host-based routing within the domain Path setup schemes selectively update local routers as users move Path setup schemes customized based on user, application, or wireless network characteristics * Micro-mobility handled locally with limited disruption to user traffic Path Setup Schemes
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII Mobile IP Internet >port 3 (4), > port 3, R R MY IP: BS IP: R R R Domain Root Router 2 Domain Root Router 1 5 BS >wireless, BS2BS3BS >port 1(wireless), Micro-Mobility
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony MY IP: BS IP: COA IP: Internet >port 2, > port 3, >wireless, HAWAII Mobile IP R R R R R Domain Root Router 2 Domain Root Router 1 5 BS BS2BS3BS4 1 Mobile IP Home Agent: > Macro-Mobility
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Simulation Topology
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Performance: Audio and Video
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony TCP - Web transfers in Mobile IP: Interaction between Tunneling and TCP Path MTU discovery results in 1 round trip wasted for each object. TCP - File transfers: 5- 15% improvement over Mobile IP Performance: TCP
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Update Rates Domain Router Router 1... BS1 BS BS1 BS20 39 users/sq. miles users moves at 112 Km/hr. base stations cover 7 Km 2 Network Model T BL BL M DB DB 16 2 IP 16YT R BDBD L RBL T BL BL H B DDB M DB DB Mobile IP Updates at Home Agent: Hawaii Updates at Domain Router: Hawaii M-IP <<1, local mobility aggregation Router 7 – Varies linearly with # of base stations – Varies O(B D 1/2 )
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Performance: Update Rates Scalability at the Domain Root Router – Number of entries: entries are from a given domain’s IP subnet -> perfect hashing for route lookup. – Number of updates: updates for Mobile IP varies linearly with the number of base stations in domain whereas in HAWAII, updates vary with the square root of number of base stations in domain. Based on FreeBSD implementation, for a typical network configuration, update ratio of Mobile IP to HAWAII is 3:1 and CPU utilization ratio is 9:1.
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Standardization: IETF SeaMoby Working Group Draft-seamoby-ietf-mm-problem-01.txt identifies the goals for a new IETF micro-mobility protocol: Mobility without changing routable IP address Use Mobile IP for inter-domain mobility Use Mobile IP for signaling from the mobile host IP version neutral Optimized routing Plug & Play Inter-technology/heterogeneous mobility support Inter-operate with existing QoS protocols * HAWAII appears an excellent fit! * Work is in IRTF now.
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Previous Foreign Agent Notification Extension (Route Optimization draft) NAI extension (NAI draft) Mobile challenge-response extension (Challenge Response draft) NAI in foreign agent advertisements to detect domain changes (Private addresses draft) Register with foreign agent while using co-located addresses Allow split Mobile-IP registrations at the foreign agent (regionalized tunnel draft) Changes from Mobile IP (rfc2002)
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII: Benefits Summary Scalability through reduced updates as micro-mobility transparent to home agents Limited disruption of traffic as Path Setup Schemes are optimized for the environment Efficiency through reduced data packet header overhead as no tunneling in a (large) home/power-up domain Ease of QoS support: unique address Reliability through soft-state Transparency to hosts that use Mobile IP Integration with existing wireless infrastructure
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Outline Motivation IP Mobility –Macro-mobility: Mobile IP –Micro-mobility: HAWAII * IP Paging –HA/FA paging –Domain paging Interworking of Wireless LANs with 3G Networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Mobile Host State Diagram “Idle” mobile hosts update network less frequently than “active” mobile hosts Network has only approximate location information for idle mobile hosts * Network determines the exact location by paging to deliver packets What is Paging?
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging Outline Motivation IP Paging Architectures Performance IETF Standardization (SeaMoby Working Group) Summary
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Paging in wireless networks (1): GPRS, UMTS Paging for voice initiated differently (MSC) from data (SGSN) + may be deployed leveraging existing infrastructure – requires separate mechanisms Specialized nodes, protocols (BSSGP) manage paging + requires no changes to intermediate routers – separate advances from other paging protocols – special failure recovery mechanisms needed Intranet MD SGSN GGSN Host Regular routing Tunneled packets using GTP Internet SGSN Radio Access Networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Paging in wireless networks (2): CDMA2000, Mobile IP Paging for voice initiated differently (MSC) from data (RAN/MSC) + may be deployed leveraging existing infrastructure – requires separate mechanisms – No paging in Mobile IP Specialized nodes, protocols (IS2001) manage paging + requires no changes to fixed hosts or routers – separate advances from other paging protocols – special failure recovery mechanisms needed MD FA HA Host Internet Regular routing Tunneled packets using Mobile IP FA Radio Access Networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony As wireless access networks migrate to IP, IP paging allows common infrastructure to support different wireless technologies –seamless merging of LAN/WAN –avoids duplication of paging protocols, resulting in cost savings deployment of sophisticated paging algorithms –leverages the support of multicast, if available –user-customized paging areas Why IP paging?
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Efficiency limit updates from mobile host when idle to conserve battery power Scalability push paging initiation closer to base station Reliability allow paging initiation to occur at any router/base station (no single point of failure) Flexibility allow for fixed, hierarchical, or user-defined paging areas IP Paging Goals
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging Architectures Internet Home Agent Foreign Agent Foreign Agent Foreign Agent R R R Domain Paging Area Mobile IP Paging Area 3 Options: Home Agent Paging – Home agent buffers packets and initiates page to all Foreign Agents – Can be controlled by corporate network – Does not scale Foreign Agent Paging – Last active Foreign agent buffers packets and initiate paging – Distributes load Domain Paging – Fully distributed, very scaleable and reliable Uniform mobility management – wireless LANs, outdoor Old FA initiates page HA initiates page Any router initiates page
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Home Agent (HA) Paging Centralized at HA Simple implementation Issues/concerns –Inefficient signaling: long delays if HA far from mobile host –Scalability at HA –Multicast-based addressing of paging area needs global visibility, scalability of paging areas
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Foreign Agent (FA) Paging Initiated at previously attached FA Distributed among different foreign agents in paging area Simple implementation Efficient: paging restricted to local domain Issues/concerns –Reliability when previous FA crashes –Requires FA deployment
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Domain Paging Initiated at any node (router/base station) in path from mobile to root router Completely distributed among different nodes in domain Highly scalable, reliable to node failures Efficient: paging restricted to local domain Issues/concerns –implementation complexity –router support
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Router operation Routing Paging entryentryStateOperation YESYESActiveRegular Forwarding YESNOActiveNo paging support NONONullForward if default route exists, else discard NOYESStandbyPaging: If (packet arrives from DRR or I am DRR) If (node is base station or no refresh from downlink port or queuesize < threshold) Initiate paging else Forward to port in paging entry Endif else Forward along default route Endif
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Implementation All three paging protocols implemented in FreeBSD Paging protocol processing in user space, data forwarding in kernel space Paging implementation does not affect fast path performance - use of virtual interfaces Implementation used to measure processing load of different paging tasks - results to drive large scale simulation
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony MY IP: BS IP: Internet >port 3, > port 3, R R R R R Domain Root Router 2 Domain Root Router 1 5 BS >wireless, BS2BS3BS4 1 2 Buffer HAWAII Paging Data Paging
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Scalability (latency) Simulation parameters –36-90 zones per domain –paging area size = 6 –real, synthetic traces –processing times from implementation HA paging needs 5 processors for comparable performance FA paging scalable Domain paging supports highest paging load
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Scalability (updates) Large Paging Area size results in fewer updates but increases latency due to higher paging processing load In FA/HA paging, updates can occur due to movement or when user is paged and found at new location In Domain paging, updates are only due to movement - results in least number of updates
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging – Reliability Results Internet Home Agent IP Paging Area R FA R R DR/HA R R R R R R Mobile IP Model Domain Model
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging – Reliability Results Domain HA FA DomainHA
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Standardization: IETF SeaMoby Working Group Draft-ietf-seamoby-paging-problem-statement-02.txt identifies need for IP paging (now RFC 3132) Draft-ietf-seamoby-paging-requirements-02.txt identifies following requirements (now RFC 3154): – minimize impact on host’s power consumption – on receiving page, host must re-establish layer three link – efficient utilization of layer two, if available – support existing mobility protocols – flexible support for different paging areas – allow arbitrary mapping between paging areas, subnets – robust against failures, packet losses * FA, Domain paging suitable candidates!
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Summary IP-based wireless access networks - efficient, cost-effective IP paging allows common infrastructure to support different wireless interfaces including CDMA, GPRS, wireless LAN etc. Proposed three paging architectures: each has its applicability – HA paging useful in small networks with complete administrative control – FA paging simple, scalable, easily deployable – Domain paging scalable, flexible, reliable, most efficient Future work – Standardization – Flexible and user-specific paging mechanisms
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Outline Motivation IP Mobility –Macro-mobility: Mobile IP –Micro-mobility: HAWAII IP Paging –HA/FA paging –Domain paging * Interworking of Wireless LANs with 3G Networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Integrated Wireless Access Networks Ubiquitous access to Internet and applications Always-on high speed packet data access Islands of multi-technology RF access networks connected to core IP network Core IP Network Radio Access Network Radio Access Network Service Provider “Home” Network Billing Authentication Mobility Service Provider “Home” Network Billing Authentication Mobility Roaming Agreements Radio Access Network The next wave of Internet access will be through high-speed wireless packet access Wide Area Wireless Local Area Wireless Hotspot/Enterprise 4G Wireless?
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Overview Goal –Integrate and wide-area wireless networks Motivation –Ability to choose where available (substantial cost-bandwidth advantage) –3G/ integration can enhance existing wireless services and offer new services. Approach –Integrate with CDMA2000 &/or UMTS access networks for data service Benefits seamless mobility wider application spectrum lower access/transport cost for high bandwidth services
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Background Infrastructure Network – low cost, high-data rate (11Mbps 54Mbps) – unlicensed spectrum potential interference – short range – ORiNOCO, Apple, Cisco, etc. 2G/2.5G/3G Network – high cost, low data rate (153kbps 2Mbps) – licensed spectrum less interference – long range – Lucent, Nortel, Nokia, Ericsson, etc. End device Various new devices being announced E.g. VisorPhone (Handspring) includes PDA with 2G+ capability: mobile phone, messaging, internet access,... Palm and Motorola announced PDA with GPRS (2.5G) capability NeoPoint, Sony, etc. claim /CDMA or /GSM prototypes Observations Dissimilar networks and infrastructure Need for current end devices and applications to adapt between one network type and another
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Public Wireless Access Networks: Why are they different? Security is a major concern where a wireless shared medium is used in a public environment –More susceptible to eavesdropping and man-in-the-middle attacks –Not behind firewall of friendly colleagues –Secure access into the enterprise Accessing service on other provider’s networks –Roaming agreements, global roaming, shared revenue agreements –Perform authentication and accounting for roaming subscribers Mobility –Efficient, seamless handoff of data sessions while moving across networks Authentication –User authenticates to the network –Authentication at different layers: L2, L3, VPN, HTTPS Integrated service across different air-interface technologies Management and Home policy –Distribute per user home policy and QoS levels of service to roamed networks –Minimize exchanges with home network through efficient protocols and optimizations QoS/ Levels of Service –Air interface contention, fair network usage, and alleviating congestion in hot spot areas –Cannot statically configure based on IP addresses Mobile Client Software –Mask complexities from the user: configuration, reauthentication, network selection
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Challenges for Public Wireless Data Access Security is a major concern where a wireless shared medium is used in a public environment Enabling roaming across networks –enable integrated service across different air-interface technologies (e.g and 3G networks) –Perform authentication and accounting for roaming subscribers –Shared revenue arrangements to allow other service provider’s subscribers on network Improving the subscriber’s experience –Minimizing subscriber interaction when roaming across networks and networks using different air interface technologies –One-time user authentication –Automatic client terminal configuration for network Being able to offer levels of service, fair network usage, and alleviating network congestion in hot spot areas
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Infrastructure Challenges Authentication, Authorization, and Accounting (AAA) –3G networks use Home Location Register (HLR) and AAA servers to perform authentication of link-layer and network-layer sessions – networks have their own link-layer authentication mechanisms Perform separate administration or Merge user authentication profiles Mobility –3G networks allow for hierarchical mobility management with link-layer handoff, micro-mobility and macro-mobility support – networks support link-layer mobility and IP mobility mechanisms Perform IP mobility or use 3G mobility mechanisms in Quality of Service (QoS) support –Large disparity in bandwidth availability between 3G and –3G networks, unlike , are designed and engineered for QoS End device adaptation and QoS support in Two approaches to address these challenges: . Interconnect 3G networks with using IP: peer-to-peer integration . Integrate into 3G networks: access network integration
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Approach 1:Peer-to-Peer Integration Overview –Different administrative domains connected through IP –Cross domain roaming is supported by using standard IP mobility, AAA Advantages –Easy to build (works today!) –Fits All-IP philosophy Disadvantages –Requires Mobile IP in end device for seamless roaming –Potentially slower handoff and inefficient data path Intranet/Internet AAA HLR Wireless 3G Network AAA M-IP Agent M-IP Agent Public/Enterprise Data Network BS 3G Air Interface BS 3G Air Interface Access Network 3G Core Network Air Interface AP AP Air Interface AP AP
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Approach 2: Access Network Integration Overview –Operate clusters under the same 3G access network –Mobility, AAA supported by same mechanisms in 3G network Advantages –Faster handoffs and more efficient transport –Integrated HLR/AAA Disadvantages –Customized 3G Gateway necessary for each network (CDMA, UMTS) results in high cost Internet Integrated 3G/ Network M-IP Agent BS 3G Air Interface BS 3G Air Interface Access Network 3G Core Network Air Interface BS BS Air Interface BS BS AAA HLR 3G Gateway
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Complete Service Picture Wireless Carrier Network 3G Access MobileStar Starbucks “Store-front” Wayport Airport/ Enterprise Wayport Airport/ Enterprise Terminal Possibilities Applications/ Content Authentication Accounting Mobility/ Roaming Agreements Corporate Network Applications/ Content Accounting/ Billing Authentication VPN 3G Access Handoff Possibilities Intertech Internetwk Handoff Intratech Intranetwk Handoff Intratech Intranetwk Handoff Intratech Internetwk Handoff Intratech Internetwk Handoff Intratech Internetwk Handoff Roaming Broker Seamless Mobility/Roaming for Subscriber/ Negotiated Rates with Partners One Bill from Wireless Carrier/ Bundled Data Package Uninterrupted Applications: Streaming, , Corporate VPN, Web Dual Interface Built-in Combined Air Card Subscriber Service Wireless Access Network Support Built-in G data card Internet
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Home AAA Home Agent Hot-spot Access Router Access Points Gateway “Home” network (3G carrier) BS 3G Wireless Access BSC PCF or SGSN Local AAA PDSN or GGSN Internet Dual-mode terminal w/ MobileIP client /3G Integration Architecture using Peer-to- Peer Approach and IP mobility Billing Servers
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Industry Security Status Problems with existing products –Same shared static key used for encryption –Weak encryption through RC4 and short keys –User access is not authenticated to network servers –Proprietary solutions do not interoperate i Working Group Solutions –Per packet authentication –Temporary encryption keys and frequent rekeying –Stronger AES encryption and longer keys –Adoption of 802.1X standard
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony What is 802.1X? Framework for port-based network access control Allows authentication & key derivation through EAP schemes –Extensible Authentication Protocol (RFC 2284) –Reuse RADIUS infrastructure to carry EAP frames –Avoids preconfiguration of encryption keys at user terminals Standard is not specific to wireless or Allows Access Points to support many different EAP schemes – working group did not mandate particular EAP scheme Internet Local AAA Home AAA “Home” Network Access Point Network 802.1X EAPOL Radius w/ EAP-Message Radius Direct to HAAA or through Broker AAA EAP support
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony EAP-SKE scheme for Security Home AAA Home Agent Gateway Internet “Home” Network EAP-SKE (Shared Key Exchange) solution –Authenticate user to Home AAA with minimal protocol exchange –Provide mutual authentication –Home-AAA dynamically generates and distributes per- user per-session keys –Use separate keys for authentication and encryption; keys are never passed over the air –Commonality with MobileIP and 3GPP2 standards Use same authentication credentials Use same keyed hash function (HMAC-MD5) –Works with 802.1X, the accepted standard for initiating authentication with access points EAP-SKE IETF draft – eap-ske-00.txt Performs Authentication, Generates Encryption key and key material 802.1X/EAPOL exchange over air Radius exchange Algorithm to construct encryption key from passed key material Goal : dynamically establish security relationship between user and public access points with no prior configuration and no subscription with owner of network
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Home AAA Home Agent “Home” network (3G carrier) Internet Roaming Agreements Among Service Providers Billing Servers Access Points Gateway Large WISP Service Provider (e.g. Wayport) Broker AAA Shared Revenue Settlement DB Access Points Gateway Access Points Gateway Roaming Agreement Large WISP (Wayport) WISP Service Aggregator Broker AAA Shared Revenue Settlement DB Roaming Agreement Small WISP (Company X) Small WISP (Company Y) Same backend infrastructure Supports 3G and
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony QoS Features for QoS over air Gold Service User Silver Service User Bronze Service User 10 Mbps Home AAA Home Agent Gateway IP QoS on access bottleneck Edge Router Access Router 10 Mbps Internet Need QoS functionality in two spots of possible congestion –IP QoS on oversubscribed access link –QoS for air interface Per user Level of Service policy obtained from Home AAA database in AAA protocol exchange –dynamic rate limiting Gateway maps user population in cells for achieving fairness and preserving service level guarantees DiffServ packet marking and traffic policing –Gateway can mark packets even with Mobile IP tunnels –Home agent marks packets for destined traffic Goal : Offering per user levels of service and fairness to subscribers in networks
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Integration Summary /3G integration provides choice of wireless internet access while allowing seamless mobility IP-based peer-to-peer interworking Solution easily extends to other types of wireless access –HDR, a, OFDM, Hiperlan2 Adapting CDMA2000 standards (security, accounting, mobility) for the environment allows client software and backend servers can support both networks Commonality across CDMA2000 and UMTS for integration with –UMTS needs to have support for IETF protocols
Mar 27, IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Conclusion IP-based wireless access networks are efficient and cost- effective Combination of HAWAII for micro-mobility and Mobile IP for macro-mobility supports seamless and scalable handoffs IP paging allows common infrastructure to support different wireless interfaces including CDMA, GPRS, Wireless LAN etc. /3G integration provides choice of wireless internet access while allowing seamless mobility